1. Field
The following description relates to image processing, and more particularly, to a technology of blending a high dynamic range (HDR) image or a plurality of images captured with different exposure settings to create multiple images.
2. Description of the Related Art
A dynamic range (DR) of a digital image is defined as a ratio of a brightness of a darkest pixel of the digital image with respect to a brightness of a brightest pixel of the digital image. However, human visual response is measured by a system known as the Human Visual System (HVS), which has a dynamic range which is much higher than dynamic ranges of conventional imaging devices such as digital cameras and monitors. In other words, the conventional imaging devices cannot capture or display all images visible to the naked human eye. Recently, demand has increased with regard to high dynamic range (HDR) images having high dynamic ranges that cannot be processed by existing conventional imaging devices.
Various methods of generating HDR images exist, and one such method is to expand the dynamic range of images by blending a plurality of images with different exposure settings.
Accordingly, there exists a conventional method of expanding the dynamic range of images by acquiring a plurality of images captured with different exposure settings, calculating an average luminance of the images and adjusting gains to be applied to the images based on the average luminance. Also, there exists another conventional method of, compensating for a luminance of each of a plurality of short-exposure or long-exposure images based on predetermined exposure settings after the images have been acquired, and then blending the images.
However, the conventional image blending methods described above may deteriorate picture quality when applied to displays with small dynamic ranges (DRs).